Finalising Flashcards
(50 cards)
Insertion anomaly
The inability to add data to the database due to the absence of other data.
Deletion anomaly
Occurs when you delete a record that may contain attributes that shouldn’t be deleted
Modification/Update anomaly
Caused by the addition of, change to, or deletion of data from a database table
Factors that impact the performance of a database
- workload
- throughput
- resources
- optimisation
- contention
Importance of adding comments to code
Not always easy to remember program code written some time ago. Comments let the reader know what the source is meant to do
Declare a list of strings items
Dim lstProgLanguages As New List (Of String)
Add items to list
lstProgLanguages.Add
Remove items to list
lstProgLanguages.Remove
HTTP
Protocol allowing unencrypted info to flow from server to client’s browser allowing sensitive info to be stolen
HTTPS
Protocol creating secure encrypted connection between server and client’s browser, thereby protecting sensitive info
Tags used to create a drop down list
<selection>
<option>
</option></selection>
<optgroup>
</optgroup>
Used to group together related items within a selected list. Makes it easier for users to make choices when looking at large lists
Internal CSS
Requires that CSS rules be placed inside the <style> and </style> tags within the <head> section of the page
External CSS
CSS rules are placed in a text file with file extension .css and the <link></link> tag is used to link test file to the HTML code
Inline CSS
CSS rules are placed inside the style attribute of each html tag
Performance testing
Tests how an application would work when used by the expected number of users
Stress testing
Tests how the application would work when used by more than the expected number of users
Portability testing
Tests the application to see how it works when moved to another device
Objectives a database driven software app must satisfy
Supporting concurrency:
The app should allow multiple users access but be able to handle concurrent updating of same data
Data integrity:
The app should allow valid and well formatted data
Security/Authentication:
the app should allow authorised users only
Fault tolerance:
The app should be able to handle potential problems gracefully
2D array
Dim int ICASS_MArks(,) As Integer
{
{68,56,76,45,79}
{34,50,57,70,60}
}
<textarea>
</textarea>
allows the user to enter multiple lines of text
<input></input>
allows only one line of text to be entered
Process that occurs when an internet user enters a URL with a domain name in a web browser
- DNS looks up the IP address of the domain name
- Web browser uses HTTP/HTTPS to send the request to the web server
- Web server responds with necessary HTML document
-Web browser then translates the HTML document into a webpage
Methods to manage security issues
- Make sure that antivirus software is installed and regularly updated
- Ensure that computers and servers are password protected
- Restricted entrance to key computer resources with unauthorised access
